There is a commercial need for shrink films that have at least one of the following desirable shrink film properties; (1) low onset shrinkage temperature, (2) a shrinkage percentage which increases gradually and in a controlled manner with increasing temperature over the temperature range where shrinkage occurs, (3) a shrink force low enough to prevent crushing of the underlying container, (4) a high ultimate shrinkage (shrinkage at the highest temperature), e.g. 60% or greater shrinkage in the main shrinkage direction at 95° C., (5) low shrinkage in the direction orthogonal to the high shrinkage direction, (6) improved film toughness so as to prevent unnecessary fracturing, breaking, tearing, splitting, bubbling, or wrinkling of the film during manufacture and prior to and after shrinkage, and (7) recyclability.
Certain commercial films are made from polyester compositions that contain 1,4-cyclohexanedimethanol residues and ethylene glycol residues. Additional commercial needs exist for materials that have improved toughness. Fulfillment of this need in the art would allow for less expensive production, reduce lost manufacturing time due to film breakage, help to expand product portfolios, and allow for film downgauging to reduce the weight of film used in each label, and improved manufacturing efficiency by reducing downtime due to film breakage.